The present invention relates to a plasma display device, and more specifically, to a plasma display device mounted on mobile objects, such as an aircraft or a vehicle.
Services provided to passengers on an aircraft include the projecting of movie and information on a screen using a video projector. Along with the recent development of the plasma display device, there are attempts to mount the plasma display device on the aircraft instead of the conventional video projector and screen.
When mounting a plasma display device on an aircraft, the display must satisfy various safety requirements. One strict requirement is the load requirement, which considers the case where the human body or objects on the aircraft collide against the glass plate of the display device due to turbulence or steerage during flight or drive.
This load requirement is called the abuse load, which is set assuming the case where a load as large as 136 kg is added to any random position on a 10-cm square glass surface.
The requirement load of a normal plasma display device is relatively small compared to the abuse load, assuming such case as where a ball and the like hit the glass surface.
In order to fulfill the above requirements, the conventional device includes a tempered glass having a thickness of approximately 3 mm mounted on the surface of a glass plate of the display module, with a gap of approximately 3 mm formed between the tempered glass and the display module body. Due to the 3-mm gap, the tempered glass will not contact the display module body even if the load deflects the tempered glass. In other words, until the deflected tempered glass reaches the glass of the display module body, the display module will receive no influence by the abuse load.
The conventional plasma display device is explained with reference to FIG. 8.
FIG. 8 is a cross-sectional view mainly showing the display module portion. A display module 3 comprising upper and lower glass plates constituting luminescent pixels is equipped with electronics 5 mounted on the back surface thereof. The electronics 5 are connected to the module 3 through flex lead 7. A tempered glass 1 is mounted on the front surface of the display module 3 with a gap 2 of approximately 3 mm formed therebetween, thereby protecting the display module 3.
As shown in FIG. 9, according to this type of display modules, even if the tempered glass 1 is deflected by the load, the load will not be added the display module 3 until the tempered glass 1 reaches the glass of the module 3, or in other words, while the deflection is smaller than the 3-mm gap 2.
Moreover, according to a general plasma display device, an aluminum alloy plate 4 having a thickness of approximately 2 mm is adhered on the back surface of the glass plate constituting the module. The aluminum alloy plate 4 is for mounting electronics 5 and power unit for driving the display device 3, and not for supporting the display module from the added load.
One method for reinforcing the device is to provide an aluminum alloy (back surface) plate 4 having a greater thickness, so that it may bear the abuse load of the aircraft. However, if the aluminum alloy plate 4 is formed thick enough to endure the load, the weight of the display is increased greatly. Therefore, such method is not preferable.
Since the conventional plasma display device is designed based on the assumption that the display is to be used under a static environment, such as at home or in the office, it is extremely difficult for the conventional device to satisfy various conditions such as strength, heat diffusion, weight and size required for mounting the display device on an aircraft or a vehicle.
The present invention aims at solving the problem. The present invention aims at providing a plasma display device capable of being used under a mobile environment, such as in the case where the plasma display device is to be mounted on an aircraft, a train, a bus, or a ship. In other words, the present invention aims at providing a plasma display device that is strong enough to satisfy various requirements such as abuse load, vibration and shock, and equipped with a heat diffusing function for diffusing the heat generated from the module, with only minimum increase in size and weight compared to the conventional display device.
According to the present invention, a reinforcement member constituted by a sandwich panel (laminated panel) formed of a honeycomb core or a corrugated core made of aluminum alloy sandwiched with aluminum alloy plates and mounted on the back surface of the display module. The reinforcement member is light, and it enables the display device to satisfy the abuse load requirements.
Moreover, according to another claim, the laminated panel is provided with a heat diffusing function.